Conventionally, crimp bonding, in which an electric wire is caulked and crimped by a terminal called open-barrel type, is usually used to connect an electric wire with a terminal in a wire harness for motor vehicles. In such a wire harness however, any moisture or the like attaching to the connection part of the electric wire and the terminal may cause progress of oxidization of the surface of a metal that is used for the electric wire and increase the resistance at the joint part. In addition, if different metals are used for the electric wire and the terminal, corrosion between different metals may progress. This progress of corrosion of the metal materials at the connection part causes cracks or contact failure at the connection part and its effect on product life is unavoidable. In recent years in particular, a wire harness having electrical wires made of aluminum alloy and terminals made of copper alloy has been in practical use, and the problem of corrosion at the joint part thereof has been noticed.
For instance, if moisture attaches to the contacting part of different metals, such as aluminum and copper, so-called electrolytic corrosion may occur due to difference in corrosion potential. Since the potential difference between aluminum and copper is large in particular, corrosion on the side of aluminum, which is an electrically base metal, progresses. Consequently, the connection between the conducting wires and crimp terminals becomes unstable, causing an increase in contact resistance or in electrical resistance due to decrease in wire diameters, and, furthermore, disconnection of the wires may occur which may result in malfunction or breakdown of the electrical components.
Disclosed is such a wire harness in which different metals are in contact with each other and resin material is filled to cover the connection parts of electrical wires and crimp terminals (Patent Document 1). Filling the resin material prevents moisture from attaching to the contact parts of electrical wires and crimp terminals.